Propagation conditions from cellular base stations to mobile stations can change rapidly given terrain, weather, the location of the mobile station, etc. If a mobile station cannot detect and establish contact with a new base station before the signal from the existing base station fades away, the call may get dropped. The current method of recognizing and establishing communication with a new base station uses a handoff list for each base station sector, where each handoff list contains handoff target sectors in all directions. When the mobile station has more than one handoff leg, the list from each sector is combined using a round-robin selection process to arrive at a handoff list usually containing 20 handoff candidates. The time required for this process is not trivial and the results can include handoff candidates that have an extremely low probability of ever being used given the current handoff state of the mobile station.
There is a need, not met in the prior art, for a method of generating and providing a handoff candidate list to a mobile station that minimizes the number of handoff candidates. For example, there is a need, not met in the prior art, of decreasing the number of handoff candidates from the current maximum number handoff candidates. Accordingly, there is a significant need for an apparatus and method that overcomes the deficiencies of the prior art outlined above.
Elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms “first”, “second”, and the like herein, if any, are used inter alia for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms “front”, “back”, “top”, “bottom”, “over”, “under”, and the like in the Description and/or in the Claims, if any, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position. Any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein may be capable of operation in other configurations and/or orientations than those explicitly illustrated or otherwise described.